A month today the Tour de France makes its Grand Départ in London. The cycling press here has been ticking off the days for months now. I have lost count of the number of press calls and media launches held by the London Mayor, Transport for London, the Metropolitan police and others. Poor old Bradley Wiggins, our Olympic gold medallist, who, as a speed specialist, is in with a shout for the opening prologue stage, has been wheeled out - literally - on innumerable occasions to promote the cause. After the publicity round, riding the 4,000km Tour will probably seem like a walk in the park.

The expectation is infectious. People are planning when and how they are going to see the greatest bike race on Earth go right past their noses. As former yellow-jersey winner Chris Boardman points out, what other sporting event on such a scale can you see for free? Even if our unpredictable British weather does its worst, it is unlikely to dampen the enthusiasm of the crowds in London and along the road to Canterbury. And no doubt ITV2 will reap the reward of vastly improved viewing figures as the Tour winds its way towards its conclusion three weeks later on the Champs Elysées.

And yet ... the Tour presently seems to be carrying on a tradition, established since the 1998 Festina team scandal, of getting its bad news out early. Following the recent revelations of a former Team Telekom soigneur, Jeff D'Hondt, the 1996 Tour winner, Bjarne Riis, who now runs the CSC squad, was forced to admit that he had used the blood-booster erythropoietin (EPO) to help him win. This was small surprise since his nickname in the pro peloton had been "Mr 60%" (referring to his abnormally high haematocrit level, an indication of EPO usage since a high natural level in a trained athlete would be in the low 40s).

And this is a race still without an undisputed winner from last year, since American rider Floyd Landis continues to fight his disqualification for a doping offence. "Landis gave us a new hero, but 48 hours later he was out," said the Tour's director, Christian Prudhomme, this week in London. "Now a new hero will arrive."

It sounds cynical, but that is exactly it, in two, crisp sentences: the cycle of doping, scandal and sacking continues, but what can you do? The Tour moves on, and the show goes on.

What chance, then, that the new hero this year will be clean? For sure, the testing regime is tougher then ever, but it will never be infallible. The chemistry of doping grows more sophisticated every year. Some of the teams are working hard to ensure that their riders are not doping. But how long can such admirable minority stances survive in the harsh commercial environment of a sport that depends on sponsorship and in which sponsors expect results?

The only way to understand the Tour de France is as a theatrical performance, in which, each year, we put aside our doubts and exercise Coleridge's "willing suspension of disbelief": we know it's probably not a clean race, but we hope it is and we want a new hero to believe in. Unfortunately, the Tour seems to subscribe to Brechtian aesthetics: almost unerringly, it comes up with an "alienation effect" to puncture those illusions of purity, fair competition and true heroes. But perhaps, deep down, that's the real-life adult drama we prefer.

Bike Doc

Dear Matt, My bike is already insured on my home policy but I've been thinking I ought to get accident and third-party insurance. However, a pretty exhaustive web search doesn't give much hope - excesses of £500 and measly accident insurance, and then only if you lose a leg or eye, etc. Am I missing something?John Morse-Brown, via email

Your best bet is to gain these insurance benefits through one of cycling's membership organisations. The Cyclists Touring Club (ctc.org.uk) includes third-party insurance and legal advice in the event of an accident as part of its standard package (at a modest £34 per year). If you join British Cycling (britishcycling.org.uk/) at its premium "gold" membership rate (£60 pa), personal accident insurance is provided as well. But cover is limited to severe and permanently disabling injuries only.

Unfortunately, insurance policies in the open market for injury or illness which, for instance, might merely interfere with your ability to work for a limited period just are expensive.